i didnt know whether to post this here or the pcm section but ill post it here.....

anyways my buddy got a 02 z28 m6(bone stock) last night went to the place that had scanned it with my tuner it shows a P0300 rand./ multiple cyl. misfire so i cleared and let him know about it. he really liked the car so he got it anyways last night he said it was idling rough so i scanned it this morning it threw 3 codes at me. the first is P0151 O2S Circuit bank 2 sensor 1, low voltage the second is P0174 fuel trim bank 2, system too lean and the third is the same P0300 random cyl misfire. i was thinking a bad O2 sensor possibly bad injector on bank 2.

so i was wondering what you guys thought could be the cause of this could be. im halfway thinking it may be a bad injector but then it shouldve thrown a cylinder specific misfire not a random. so your thoughts and input would be greatly appreciated. thanks

edit* it has a little over 68,000 and they just replaced a part in the tranny ill have him ask what exactly it was

 

Id run injector cleaner through it, replace both front O2 sensors, replace plugs and wires, clean the MAF and air filter, and listen around the engine for an intake vacuum leak. Then take it from there.

 

+1. im with him ^

 

+2 Sounds like good advice. In the same order too. If you can, take a look under the car to make sure the 02 wires aren't fried. They're pretty close to the exhaust even stock.

 

you could Sea Foam it, if your cheep, or run out of options